Sun November 20, 2011 By: Mahalakshmi Raghavan

about dna

Expert Reply
Tue November 22, 2011
DNA molecule shows a double helical structure. This structure was first described by James Watson and Francis Crick in 1953.
The structure of DNA is illustrated by a right handed double helix, with about 10 nucleotide pairs per helical turn. Each spiral strand, composed of a sugar phosphate backbone and attached bases, is connected to a complementary strand by hydrogen bonding (non- covalent) between paired bases, adenine (A) with thymine (T) and guanine (G) with cytosine (C).

Adenine and thymine are connected by two hydrogen bonds (non-covalent) while guanine and cytosine are connected by three.
Genetic information is carried in the linear sequence of nucleotides in DNA. Duplication of the genetic information occurs by the use of one DNA strand as a template for formation of a complementary strand. The genetic information stored in an organism's DNA contains the instructions for all the proteins synthesized by the organism.
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